The production rate of drinking water treatment plants in the Netherlands is currently often directly related to the level in the clear water reservoir. This results in many production rate changes, and the daily peak demands are not completely levelled off in the clear water reservoir. A recently developed control algorithm, based on an adaptive demand prediction, can achieve a more stable production pattern with a minimum of flow changes. The implementation of the algorithm at several treatment plants has led to a significant optimisation of the treatment process. A more stable treatment process leads to better clear water quality and to less energy consumption. A future combination of a control algorithm and a qualitative model opens up the possibilities for further optimisation of the treatment process and to a consistent clear water quality.